gdb/arch/riscv.c

   1 /* Copyright (C) 2018-2024 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include "gdbsupport/common-defs.h"
  19 #include "riscv.h"
  20 #include <stdlib.h>
  21 #include <unordered_map>
  22
  23 #include "../features/riscv/32bit-cpu.c"
  24 #include "../features/riscv/64bit-cpu.c"
  25 #include "../features/riscv/32bit-fpu.c"
  26 #include "../features/riscv/64bit-fpu.c"
  27 #include "../features/riscv/rv32e-xregs.c"
  28
  29 #ifndef GDBSERVER
  30 #define STATIC_IN_GDB static
  31 #else
  32 #define STATIC_IN_GDB
  33 #endif
  34
  35 /* See arch/riscv.h.  */
  36
  37 STATIC_IN_GDB target_desc_up
  38 riscv_create_target_description (const struct riscv_gdbarch_features features)
  39 {
  40   /* Now we should create a new target description.  */
  41   target_desc_up tdesc = allocate_target_description ();
  42
  43 #ifndef IN_PROCESS_AGENT
  44   std::string arch_name = "riscv";
  45
  46   if (features.xlen == 4)
  47     {
  48       if (features.embedded)
  49         arch_name.append (":rv32e");
  50       else
  51         arch_name.append (":rv32i");
  52     }
  53   else if (features.xlen == 8)
  54     arch_name.append (":rv64i");
  55   else if (features.xlen == 16)
  56     arch_name.append (":rv128i");
  57
  58   if (features.flen == 4)
  59     arch_name.append ("f");
  60   else if (features.flen == 8)
  61     arch_name.append ("d");
  62   else if (features.flen == 16)
  63     arch_name.append ("q");
  64
  65   set_tdesc_architecture (tdesc.get (), arch_name.c_str ());
  66 #endif
  67
  68   long regnum = 0;
  69
  70   /* For now we only support creating 32-bit or 64-bit x-registers.  */
  71   if (features.xlen == 4)
  72     {
  73       if (features.embedded)
  74         regnum = create_feature_riscv_rv32e_xregs (tdesc.get (), regnum);
  75       else
  76         regnum = create_feature_riscv_32bit_cpu (tdesc.get (), regnum);
  77     }
  78   else if (features.xlen == 8)
  79     regnum = create_feature_riscv_64bit_cpu (tdesc.get (), regnum);
  80
  81   /* For now we only support creating 32-bit or 64-bit f-registers.  */
  82   if (features.flen == 4)
  83     regnum = create_feature_riscv_32bit_fpu (tdesc.get (), regnum);
  84   else if (features.flen == 8)
  85     regnum = create_feature_riscv_64bit_fpu (tdesc.get (), regnum);
  86
  87   /* Currently GDB only supports vector features coming from remote
  88      targets.  We don't support creating vector features on native targets
  89      (yet).  */
  90   if (features.vlen != 0)
  91     error (_("unable to create vector feature"));
  92
  93   return tdesc;
  94 }
  95
  96 #ifndef GDBSERVER
  97
  98 /* Wrapper used by std::unordered_map to generate hash for feature set.  */
  99 struct riscv_gdbarch_features_hasher
 100 {
 101   std::size_t
 102   operator() (const riscv_gdbarch_features &features) const noexcept
 103   {
 104     return features.hash ();
 105   }
 106 };
 107
 108 /* Cache of previously seen target descriptions, indexed by the feature set
 109    that created them.  */
 110 static std::unordered_map<riscv_gdbarch_features,
 111                           const target_desc_up,
 112                           riscv_gdbarch_features_hasher> riscv_tdesc_cache;
 113
 114 /* See arch/riscv.h.  */
 115
 116 const target_desc *
 117 riscv_lookup_target_description (const struct riscv_gdbarch_features features)
 118 {
 119   /* Lookup in the cache.  If we find it then return the pointer out of
 120      the target_desc_up (which is a unique_ptr).  This is safe as the
 121      riscv_tdesc_cache will exist until GDB exits.  */
 122   const auto it = riscv_tdesc_cache.find (features);
 123   if (it != riscv_tdesc_cache.end ())
 124     return it->second.get ();
 125
 126   target_desc_up tdesc (riscv_create_target_description (features));
 127
 128   /* Add to the cache, and return a pointer borrowed from the
 129      target_desc_up.  This is safe as the cache (and the pointers
 130      contained within it) are not deleted until GDB exits.  */
 131   target_desc *ptr = tdesc.get ();
 132   riscv_tdesc_cache.emplace (features, std::move (tdesc));
 133   return ptr;
 134 }
 135
 136 #endif /* !GDBSERVER */